The general aim of the investigation is to determine some of the factors that influence axonal regeneration. The basic questions that underlie this study are 1) what are the stimuli that initiate axonal growth, 2) what factors influence the rate of elongation of the growing axons, and 3) what interactions may occur between the growing axons and the cells with which it comes in contact. The answers to these questions may provide clues to procedures for promoting the repair of damaged nervous tissue. Some of the specific subjects of the proposed investigation are the mechanisms of axonal transport of meterials in normal and regenerating nerve cells, alterations in neuronal metabolism in the course of regeneration and the morphological properties of the emerging axons.